1. Field of the Invention
The present invention relates to an electronic flashing apparatus and camera system having an automatic zooming mechanism capable of modifying illuminating angles automatically by changing zooming positions.
2. Related Background Art
There has been traditionally an electronic flashing apparatus and camera system having an automatic zooming mechanism to modify illuminating angles automatically by changing the zooming positions of the flashing unit on the basis of the communication data from the camera, i.e., a focal length information from its photographing lens.
Meanwhile, there has been available a wide adapter or teleadapter as a device to change illuminating angles to the wide angle side or to the telescopic side.
Attempting to obtain flashing angles in a wide range by an automatic zooming mechanism results in a larger and heavier zooming mechanism, making its practicability deficient. Therefore, if illuminating angles beyond a variable range are required, a combined use of the wide adapter or teleadapter is considered.
Traditionally, there has been an electronic flashing apparatus capable of shifting its display of illuminating angles to the wide angle side without an automatic zooming mechanism but by interrelatedly working with a wide adapter attached thereto. In a case of an electronic flashing apparatus having an automatic zooming mechanism, it is possible to change the display of illuminating angles if the wide adapter or teleadapter is used.
However, in an electronic flashing apparatus having an automatic zooming mechanism, there is a problem that cannot be solved just by changing the display of illuminating angles when the wide adapter or teleadapter is combinably used.
More precisely, the fundamental objective of the automatic zooming mechanism in the electronic flashing apparatus is to set an appropriate illuminating angle automatically on the basis of the focal length information from the photographing lens. Nevertheless, if the wide adapter or teleadapter is attached, the illuminating angle based on the focal length information from the photographing lens is caused to be different from the actual illuminating angle, creating the following problem:
(1) In the case of a wide adapter to be attached.
When a wide adapter is attached, illuminating angles are shifted to the wide angle side, so that there occurs a trouble such as an eclipse. However, when the wide adapter is attached, the guide number is always lowered with the result that energy is wastefully consumed because not only the photographing distance is reduced in an area where no wide adapter is otherwise required but an amount of emission is increased. For example, let it be assumed that when an wide adapter is attached to an automatic zooming mechanism having illuminating angles corresponding to 24 to 85 mm, the illuminating angle becomes such as corresponding to 20 to 70 mm. Now, if a zoom lens of 20 to 35 mm is used for a photographing lens, it is necessary to attach a wide adapter when the focal length is less than 24 mm. However, no wide adapter is needed if the focal length is 24 to 35 mm, and in this range where no wide adapter is needed, such a problem as mentioned above is encountered.
(2) In the case of a teleadapter to be attached.
The problem is more serious when a teleadapter is attached. In this case, as the illuminating angles are shifted to the telescopic side, eclipse is generated, making it impossible to use any automatic zooming at all.